Cancer is characterized by uncontrolled cell growth, and such abnormal cell growth forms a mass of cells called a tumor, which penetrates into surrounding tissues, and, in severe cases, causes metastasis into other organs of the body. Academically, tumors are called neoplasia. Cancer affects all tissues and organs of the body at various prevalence rates.
Especially, brain cancer (malignant brain tumor) causes great damage to the brain, and the survival rate of brain cancer patients is very low. Surgical excision is most effective in existing therapies for brain cancer. However, in many cases, surgery is impossible depending on the type or location of brain cancer, and complete excision results in a very high risk of postoperative complications. In addition, the brain has brain-blood barrier (BBB) that suppresses the penetration of drugs, and thus in order to treat brain cancer through chemotherapy using anticancer drugs, a higher concentration of anticancer drugs compared with other cancers needs to be administered, causing serious side effects in the other organs of the body.
Therefore, with respect to the treatment of brain cancer, there is a continuing need for therapeutic agents having excellent anticancer effects and no difficulty in passing through BBB.
The present inventors have already received patent rights of technical features wherein tetraarsenic hexoxide purified from natural arsenolite containing arsenic through separation and purification techniques showed cancer metastasis suppressing effects in animal experiments and had excellent anticancer treatment effects when administered to end-stage cancer patients with uterine cancer, bladder cancer, lung cancer, maxillary sinus cancer, kidney cancer, and the like (Korean Patent No. 272835).
The present inventors, as a result of continuous research on arsenic, revealed that tetraarsenic hexoxide having 99% or more of tetraarsenic hexoxide crystalline polymorph a can be produced by a novel preparation method, different from the method disclosed in the above registered patent, and a composition containing such tetraarsenic hexoxide has a remarkable effect on brain cancer prevention or treatment, and completed the present invention.
Meanwhile, it has been previously reported that tetraarsenic hexoxide induced the inhibition of malignant glioma cell invasion (J Neurosurg 121: 1483-1491, 2014), but this literature does not disclose what type of crystalline polymorph the tetraarsenic hexoxide has, and it was verified that a composition containing 99% or more of tetraarsenic hexoxide crystalline polymorph a, prepared by the preparation method of the present invention, had a better brain cancer treatment effect than the tetraarsenic hexoxide disclosed in the above literature.